CN103595442B - Cell search apparatus, receiver and method thereof - Google Patents

Abstract

The invention provides a cell search device, a receiver and a method thereof. The device includes: the first processor is used for carrying out correlation processing on the received signal and the auxiliary synchronous local sequence so as to obtain a correlation value of the received signal and the auxiliary synchronous local sequence; a first detector for detecting at least one maximum correlation value from among correlation values of the acquired reception signal and the secondary synchronization sequence; a first calculator, configured to calculate a metric value corresponding to each maximum correlation value, where the metric value is a ratio of the maximum correlation value to an average correlation value, and the average correlation value is an average value of correlation values in a cyclic prefix type determined according to the maximum correlation value; the first decider is used for comparing the metric value calculated by the first calculator with a preset value so as to determine a candidate standby cell serving as a cell search. By the device, the candidate standby cell can be accurately detected.

Description

Cell search device, receiver and method thereof

technical field

The invention relates to communication network technology, in particular to a cell search device, a receiver and a method thereof.

Background technique

In the Long Term Evolution/Long Term Evolution Advanced (LTE/LTE-A, Long Term Evolution/Long Term Evolution Advanced) system, the process of realizing time synchronization and frequency synchronization between the user terminal and the cell, and obtaining and detecting the cell signal is called cell search. The UE needs to periodically search for neighboring cells to update connected cells and find candidate cells that can be used for handover.

Currently, the UE performs cell search based on a Primary Synchronization Signal (PSS: Primary Synchronization Signal) and a Secondary Synchronization Signal (SSS: Secondary Synchronization Signal). Wherein, the cell search is generally divided into two stages.

In the first stage of the cell search, the primary synchronization channel (PSCH: Primary Synchronization Channel) is blindly detected, that is, the received signal is correlated with the primary synchronization sequence, and the number and symbol timing of the primary synchronization sequence are determined;

In the second stage of cell search, based on the number of the primary synchronization sequence and symbol synchronization information determined in the first stage, the secondary synchronization channel (SSCH: Secondary Synchronization Channel) is detected, that is, based on the primary synchronization channel determined in the first stage The number of the synchronization sequence and the symbol synchronization information are used to obtain the secondary synchronization sequence, and the received signal is correlated with the secondary synchronization sequence to obtain a correlation value. From the obtained correlation value, the peak value is found and the measurement value is calculated. The threshold value is compared to determine the secondary synchronization sequence number (cell group identification (Group ID)), cyclic prefix type (CP type) and frame synchronization information (frame timing). Currently, there are two types of cyclic prefix (CP): regular CP and extended CP.

However, the inventor found the following problems in the prior art in the process of realizing the present invention: the signal received by the user equipment UE will fluctuate, especially the LTE TDD system has uplink and downlink and guard intervals, and the signal often has a long string of all-zero sequences and For high-power signals, once the detection result in the first stage is inaccurate, the wrong sequence number and synchronization information are detected. In this way, in the second stage, when the corresponding secondary synchronization sequence signal is obtained, there may be SSS obtained for the conventional CP The sequence is a signal with high power, and for the extended CP, the acquired SSS sequences are all zero sequences. In this way, when calculating the measurement value (peak-to-average ratio), since the average value of the correlation value is the average value of the average value of the correlation value of the conventional CP and the average value of the average value of the correlation value of the extended CP, for the extended CP, the correlation The average of the values is almost zero. Therefore, the metric value is always larger than the preset value, and detection errors occur. There is currently no solution to the above problem.

It should be noted that the above introduction of the technical background is only for the convenience of a clear and complete description of the technical solution of the present invention, and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are known to those skilled in the art just because these solutions are described in the background of the present invention.

Contents of the invention

Embodiments of the present invention provide a cell search device, a receiver and a method thereof, which can make cell search results accurate and solve the above problems.

According to an aspect of an embodiment of the present invention, a cell search device is provided, and the device includes:

a first processor, the first processor is configured to perform correlation processing on the received signal and the secondary synchronous local sequence, so as to obtain a correlation value between the received signal and the secondary synchronous local sequence;

a first detector for detecting at least one maximum correlation value from the correlation values;

A first calculator, the first calculator is used to calculate the metric value corresponding to each maximum correlation value, the metric value is the ratio of the maximum correlation value to the average correlation value, wherein the average correlation value is determined according to the maximum correlation value The average value of the correlation value when the cyclic prefix type of ;

A first decision unit, where the first decision unit is used to compare the metric value calculated by the first calculator with a preset value, so as to determine a candidate standby cell for cell search.

Another aspect according to an embodiment of the present invention provides a cell search method, the method comprising:

performing correlation processing on the received signal and the secondary synchronous local sequence to obtain a correlation value between the received signal and the secondary synchronous local sequence;

detecting at least one maximum correlation value from the correlation values;

Calculate the metric value corresponding to each maximum correlation value, the metric value is the ratio of the maximum correlation value to the average correlation value, where the average correlation value is the average value of the correlation value when the cyclic prefix type determined according to the maximum correlation value is used value;

The calculated metric value is compared with a preset value to determine a candidate backup cell for cell search.

According to another aspect of an embodiment of the present invention, a receiver is provided, and the receiver includes the above cell search apparatus.

It can be seen from the above-mentioned embodiments that when performing cell search, when calculating the metric value, the average correlation value adopts the average value of the correlation value when the CP type corresponding to the maximum correlation value is used, so that the cell search can be performed accurately, which solves the problem of the prior art. the problems mentioned above.

With reference to the following description and accompanying drawings, there are disclosed in detail specific embodiments of the invention, indicating the manner in which the principles of the invention may be employed. It should be understood that embodiments of the invention are not limited thereby in scope. Embodiments of the invention encompass many changes, modifications and equivalents within the spirit and scope of the appended claims.

Features described and/or illustrated with respect to one embodiment can be used in the same or similar manner in one or more other embodiments, in combination with, or instead of features in other embodiments .

It should be emphasized that the term "comprising/comprising" when used herein refers to the presence of a feature, integer, step or component, but does not exclude the presence or addition of one or more other features, integers, steps or components.

Description of drawings

FIG. 1 is a schematic diagram of the structure of a cell search device according to Embodiment 1 of the present invention;

FIG. 2 is a schematic diagram of the structure of a cell search device according to Embodiment 2 of the present invention;

FIG. 3 is a flow chart of a cell search method according to Embodiment 3 of the present invention;

FIG. 4 is a flowchart of a cell search method according to Embodiment 4 of the present invention;

Fig. 5 is a schematic diagram of the structure of a receiver according to Embodiment 5 of the present invention.

Detailed ways

Various embodiments of the present invention will be described below in conjunction with the accompanying drawings. These embodiments are illustrative only, and do not limit the present invention. In order to enable those skilled in the art to easily understand the principles and implementations of the present invention, the implementations of the present invention will be described by taking the cell search of the LTE/LTE-A system as an example. However, it should be noted that the embodiments of the present invention are applicable to all communication systems that perform cell search.

FIG. 1 is a schematic diagram of the structure of a cell search device according to Embodiment 1 of the present invention. As shown in FIG. 1 , the cell search device 100 includes: a first processor 101, a first detector 102, a first calculator 103 and a first decision unit 104; wherein,

The first processor 101 is configured to perform correlation processing on the received signal and the secondary synchronous local sequence, so as to obtain a correlation value between the received signal and the secondary synchronous local sequence;

A first detector 102, configured to detect at least one maximum correlation value from the correlation values;

The first calculator 103 is configured to calculate a metric value corresponding to each maximum correlation value, where the metric value is a ratio of the maximum correlation value to an average correlation value, wherein the average correlation value adopts a cyclic prefix determined according to the maximum correlation value The average value of the correlation value when type;

The first decision unit 104 is configured to compare the metric value calculated by the first calculator 103 with a preset value, so as to determine a candidate backup cell for cell search.

In this embodiment, when the first calculator 103 calculates the measurement value, if the CP type corresponding to the maximum correlation value is a normal CP, then the average correlation value is the average value of the correlation values of the normal CP; if the maximum The CP type corresponding to the correlation value is an extended CP, and the average correlation value is an average value of the correlation values when the CP is extended.

In the foregoing embodiment, the first processor 101 may use any existing technology to perform correlation processing on the received signal and the secondary synchronous local sequence to obtain a correlation value. Wherein, the secondary synchronization local sequence can be determined according to the detection result of the PSS, that is, the number of the primary synchronization sequence and the symbol synchronization information; the first decision unit 104 determines that the candidate backup cell is detected when the comparison result is that the measurement value is greater than the preset value (GID, CP and frame timing corresponding to the maximum correlation value), otherwise no candidate backup cell is detected.

It can be seen from the above-mentioned embodiment that in the second stage of cell search, when the first calculator 103 calculates the metric value, the average correlation value adopts the average value of the correlation value of the CP type corresponding to the maximum correlation value instead of the current conventional The mean value of the correlation value of the CP and the extended CP is averaged, so that the cell search can be performed accurately, and the above-mentioned problems existing in the prior art are solved.

Fig. 2 is a schematic diagram of the structure of a cell search device according to Embodiment 2 of the present invention. As shown in Figure 2, the cell search device 200 includes: a first processor 201, a first detector 202, a first calculator 203, and a first decision unit 204; wherein, the functions of the above-mentioned components are similar to those in Embodiment 1, I won't repeat them here.

As shown in FIG. 2, the cell search apparatus 200 further includes: a second calculator 205, the second calculator 205 is used to calculate the average value of the correlation value during the normal cyclic prefix, and/or calculate the average value of the correlation value during the extended cyclic prefix average value.

In this embodiment, the second calculation unit 205 uses the correlation value obtained by the first processor 201 to calculate the average value of the correlation value during the normal CP, and/or calculate the average value of the correlation value during the extended CP, which can be based on actual It depends.

In this embodiment, when the number of the largest correlation value detected by the first detector 202 is one, or the number of the largest correlation value is more than one and the corresponding cyclic prefix types are the same, the second calculator 205 only It is only necessary to calculate the average value of the correlation values of one CP type. Which CP type to calculate the average value of the correlation value depends on the CP type corresponding to the maximum correlation value.

In this embodiment, when the number of the largest correlation values detected by the first detector 202 is more than one and the corresponding cyclic prefix types are different, the second calculator 205 needs to calculate the average value of the correlation values of the two CP types That's it.

In addition, the cell search device 200 may further include a memory 206 for storing the average value calculated by the second calculator 205 . In addition, the correlation value obtained by the first processor 201 may also be stored (the connection between the first processor 201 and the memory 206 is not shown in the figure). This part is optional.

In this embodiment, as shown in FIG. 2, the cell search device 200 may further include a second processor 207, configured to obtain the secondary Synchronize local sequences. The secondary synchronization sequence acquired by the second processor 207 is used by the first processor 201 .

In addition, the cell search device 200 may also include a third processing unit (not shown in the figure), which is used to perform blind detection on the primary synchronization channel (PSCH: Primary Synchronization Channel), that is, to perform correlation matching between the received signal and the primary synchronization sequence to determine The number of the main synchronization sequence and symbol synchronization information (symbol timing). The third processor is an optional component, and the receiver using the cell search apparatus 200 already includes this component, so this component can be omitted.

It can be known from the above embodiments that in the second stage of the cell search, the first calculation unit 203 can use the average value calculated by the second calculation unit 205 to calculate the measurement value, therefore, the cell search can be performed accurately, which solves the problem of the prior art the problems mentioned above. And the second calculation unit 205 may determine to calculate the average value of the correlation values of one type of CP or the average value of the correlation values of two CPs according to the actual situation.

Fig. 3 is a flowchart of a cell search method according to Embodiment 3 of the present invention. As shown in Figure 3, the method includes:

Step 301, performing correlation processing on the received signal and the secondary synchronous local sequence to obtain a correlation value between the received signal and the secondary synchronous local sequence;

Wherein, any existing method can be used for correlation processing, and the secondary synchronization local sequence can be determined according to the detection result of the PSS, that is, the number of the primary synchronization sequence and symbol synchronization information, which will not be repeated here.

Step 302, detecting at least one maximum correlation value from the obtained correlation values;

In this embodiment, the maximum number of correlation values may be one or more, and any existing technology may be used for detection.

Step 303, calculate the metric value corresponding to each maximum correlation value, the metric value is the ratio of the maximum correlation value to the average correlation value, wherein the average correlation value adopts the correlation value when the cyclic prefix type determined according to the maximum correlation value is used average of.

Step 304, comparing the calculated metric value with a preset value to determine a candidate backup cell for cell search;

Among them, the judgment method is similar to the existing technology, that is, when the comparison result is greater than the preset value, it can be determined that the candidate backup cell has been detected, and the corresponding information is the GID, CP and frame timing corresponding to the maximum correlation value; otherwise, it can be determined that no cell has been detected. out of candidate spare cells.

It can be seen from the above-mentioned embodiment that in the second stage of cell search, in step 303, the average correlation value adopts the average value of the correlation value of the CP type corresponding to the maximum correlation value instead of the correlation value of the current conventional CP and extended CP The average of the average value of the cell can be accurately searched, which solves the above-mentioned problems existing in the prior art.

In this embodiment, the method may further include: calculating an average value of correlation values in a normal cyclic prefix, and/or calculating an average value of correlation values in an extended cyclic prefix.

In this embodiment, the average value of the correlation values of one type of CP may be calculated according to the actual situation, or the average value of the correlation values of two types of CPs may be calculated. For example, when the number of the largest correlation value is 1, or the number of the largest correlation value is more than one and the corresponding cyclic prefix types are the same, the average value of the correlation values when calculating the regular cyclic prefix, or the calculation of the extended cyclic prefix The average value of the correlation value at time;

When the maximum number of correlation values is more than one and the corresponding cyclic prefix types are different, the second calculator is specifically used to calculate the average value of the correlation value in the normal cyclic prefix and the average value of the correlation value in the extended cyclic prefix value.

The cell search method in the embodiment of the present invention will be described in detail below in conjunction with the cell search apparatus in the embodiment of the present invention. As shown in Figure 4, the cell search method includes:

Step 401, performing blind detection on the Primary Synchronization Channel (PSCH: Primary Synchronization Channel);

In this embodiment, the primary synchronization channel signal is received, the received signal is correlated with the primary synchronization sequence, and the sector cell index (sector cell index) and primary synchronization sequence synchronization information are determined, that is, the number and symbol synchronization information of the primary synchronization sequence are determined (symbol timing).

Wherein, the correlation matching between the received signal and the main synchronization sequence can be realized by any existing method, which will not be repeated here;

This step can be implemented by the third processor of the cell search apparatus 200, and this step is optional.

Step 402, obtain the secondary synchronization local sequence according to the obtained synchronization information of the primary synchronization sequence;

In this embodiment, since the relative positions of the primary and secondary synchronization sequences in the system are fixed, according to the synchronization information of the primary synchronization sequence obtained in step 401, the position of the secondary synchronization local sequence signal can be known.

Step 403: Receive the secondary synchronization signal SSS, perform correlation matching on the received signal and the secondary synchronization local sequence, and obtain multiple correlation values;

In this embodiment, these correlation values can be obtained by using any existing correlation algorithm. The correlation value can be expressed as: C(cp,gid,frametim)=Corr(y _SSS (cp),SSS _replica (gid,frametim)); (1)

In the above formula (1), C(cp,gid,frametim) represents the obtained correlation value; cp represents the cyclic prefix; gid represents the group ID (Group ID); frametim represents the frame timing; y _SSS (cp) represents the received Secondary synchronization signal, SSS _replica (gid, frametim) represents the secondary synchronization local sequence; Corr(*) represents the formula for correlation calculation.

For example, the following formulas can be specifically used for correlation processing, but not limited to the following correlation processing manners. C(cp,gid,frametim)=|∑y _SSS (cp)×(SSS _replica (gid,frametim))| ² .

Wherein, the frequency domain form y _SSS (cp) of the received secondary synchronization signal is multiplied and summed by the secondary synchronization local sequence (SSS _replica (gid, frametim)), and finally the above sum is taken as a modulo square value.

Step 404, detecting at least one maximum correlation value from the correlation values;

In this embodiment, peak detection can be performed to find the largest correlation value from the correlation values obtained in formula (1), where the largest one or the largest multiple correlation values are selected from the correlation values obtained in step 403 Value, there may be one CP type or two CP types in the selected maximum candidate, expressed as:

$\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; cp</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; gid</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; frame\; time</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; cp</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}}{\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; \{</span>{<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; cp</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Step 405, calculating the average correlation value;

In this embodiment, according to the CP type corresponding to the maximum correlation value, the average correlation value is the average value of the correlation value during the conventional CP, or the average value of the correlation value during the extended CP;

When calculating the average correlation value, one average correlation value or two average correlation values can be calculated according to the actual situation, and the calculated average correlation value can also be stored;

For example, when the number of the largest correlation value is 1, or the number of the largest correlation value is more than one and the corresponding cyclic prefix types are the same, it is only necessary to calculate the average value of the correlation values in the conventional cyclic prefix, or calculate the extended The average value of the correlation value at the time of the cyclic prefix is enough;

When the number of the largest correlation value is more than one and the corresponding cyclic prefix types are different, the second calculator is specifically used to calculate the average value of the correlation value in the conventional cyclic prefix and the average value of the correlation value in the extended cyclic prefix value;

In this embodiment, the average value of the correlation value at conventional CP can be expressed as:

$\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; cp</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; normalCP</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}}{\mathrm{<span\; class="notranslate">\; average</span>}}<span\; class="notranslate">\; \{</span>{<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; cp</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In this embodiment, the average value of the correlation value when expanding the CP can be expressed as:

$\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; cp</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; extendCP</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}}{\mathrm{<span\; class="notranslate">\; average</span>}}<span\; class="notranslate">\; \{</span>{<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; cp</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Step 406, calculating a metric value corresponding to each maximum correlation value, and comparing the calculated metric value with a preset value to determine a candidate backup cell for cell search;

In this embodiment, the metric value is expressed as Γ(cp _opt , gid _opt , frametim _opt ), which is the ratio of the maximum correlation value to the average correlation value, which can be expressed by formula (5):

$\mathrm{<span\; class="notranslate">\; \&Gamma;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; cp</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; gid</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; frame\; time</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}\frac{\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; cp</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; gid</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; frame\; time</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}& {\mathrm{<span\; class="notranslate">\; cp</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; normalCP</span>}\\ \frac{\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; cp</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; gid</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; frame\; time</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}& {\mathrm{<span\; class="notranslate">\; cp</span>}}_{\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; extendCP</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

Wherein, the average correlation value is calculated by means of the following formulas (3) and (4), which will not be repeated here. In formula (5), normalcp means normal CP, and extendcp means extended CP.

In addition, the judgment method is similar to the prior art, that is, when the comparison result of the metric value and the preset value is that the metric value is greater than the preset value, it can be determined that a candidate backup cell has been detected, and the corresponding information is the GID corresponding to the maximum correlation value , CP and frame timing, otherwise it can be determined that no candidate backup cell has been detected.

In this embodiment, when calculating the metric value Γ(cp _opt , gid _opt , frametim _opt ) in step 406, the above-mentioned formulas (3) and (4) are used to calculate the average correlation value, so that the final detection result can be accurate , which solves the problems existing in the prior art.

However, in the prior art, when calculating the average correlation value, the following formula (6) is used for calculation, which may lead to false detection.

$\underset{\mathrm{<span\; class="notranslate">\; cp</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}}{\mathrm{<span\; class="notranslate">\; average</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; \{</span>\underset{\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}}{\mathrm{<span\; class="notranslate">\; average</span>}}<span\; class="notranslate">\; \{</span>{<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; normalcp</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}}{\mathrm{<span\; class="notranslate">\; average</span>}}<span\; class="notranslate">\; \{</span>{<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; extendcp</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; gid</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; frame\; time</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; \}</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

In formula (6), normalcp means normal CP, and extendcp means extended CP. is the average value of the correlation value when expanding the CP; is the average value of the correlation values at normal CP.

It can be seen from the above embodiments that the average value of the correlation values of the CP type corresponding to the maximum correlation value is used to calculate the measurement value and make a judgment, so that the cell search result is accurate, and the problems in the prior art are solved. In addition, when calculating the average value of the correlation values, one type of average value or two types of average values may be calculated according to actual conditions.

Fig. 5 is a schematic structural diagram of a receiver according to Embodiment 5 of the present invention. The receiver 500 includes a cell search unit, and the cell search unit is the same as the cell search apparatus described in Embodiments 1 and 2 above.

For example, the receiver 500 is a mobile phone, and this figure is only exemplary; the mobile phone 500 may also have other types of circuit components to supplement or replace the operating circuit to implement communication functions or other functions. Obviously, the mobile phone 500 does not necessarily include all the components shown in FIG. 5 , for example, the camera 506 may not be included.

Specifically, the mobile phone 500 includes a main control circuit 501 , a transceiver 502 , an input unit 503 , an audio processing unit 504 , a memory 505 , a camera 506 , a display 507 , a power supply 508 , and a cell search unit 510 . The main control circuit 501 , also sometimes referred to as a controller or operating controls, which may include a microprocessor or other processor device and/or logic device, receives inputs and controls the operation of various components of the mobile phone 500 .

As usual, the input unit 503 provides various user input operations. For example, the input unit 503 generally includes alphanumeric keys for allowing input of alphanumeric information, such as phone numbers, phone lists, contact information, remarks, and the like. In addition, the input unit 503 may include specific function keys, such as a "call send" key for initiating or answering a call, a "call end" key for ending or "hanging up" a call, and a channel recommendation key. Alternatively or alternatively, the input unit 503 may be a touch screen. The keys or key-like functions may also be implemented as a touch screen in relation to the display 507 .

As usual, a camera 506 is used to capture image data. The image data captured by the camera 506 is provided to the main control circuit 501 for use in a conventional manner, for example, storage, transmission and the like.

The display 507 can be, for example, an LCD display, but is not limited thereto. As usual, the display 507 displays information such as work status, time, phone number, contact information, various navigation menus, etc. to the user, so that the user can use various functions of the mobile phone 500 . The display 507 may also be used to visually display content received by the mobile phone 500 and/or content retrieved from the memory 505 of the mobile phone 500 .

The mobile phone 500 includes an antenna 509 coupled to the transceiver 502 . Transceiver 502 includes a radio frequency transmitter and receiver for sending and receiving signals via antenna 509 .

Additionally, transceiver 502 is also coupled to speaker 504-2 and microphone 504-1 via audio processing unit 504 to provide audio output via speaker 504-2 and to receive audio input from microphone 504-1. Audio processing unit 504 may include any suitable buffers, decoders, amplifiers, and the like. In addition, the audio processing unit 504 is also coupled to the main control circuit 501, so that recording can be made on the mobile phone 1 through the microphone 504-1, and audio signals stored in the memory 505 can be played through the speaker 504-2.

The memory 505 may be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory, or other suitable devices. The memory 505 includes, for example: a buffer, which is used to cache data; an application/function storage unit, which is used to store an application program and a function program or store an operation process to be executed by the main control circuit 501; a data storage unit, which is used to store a representation The device type of the mobile phone, here is the code of the mobile device, in addition, the correlation value and the average value A and B of the correlation value calculated by the mobile phone 500 can also be stored; and the driver storage part, the driver storage part Drivers for components of the mobile phone 500, such as a driver for the cell search unit 510, may be stored.

The power supply 508 is used to provide power to the mobile phone 500 .

In this embodiment, the structure of the cell search unit 510 is similar to that of the cell search apparatuses in Embodiments 1 and 2, and will not be repeated here.

In addition, if the cell search unit 510 does not include a third processor (not shown), the mobile phone 500 also needs to include a third processor (not shown).

The various components of the mobile phone 500 may be implemented by dedicated hardware, firmware, software or a combination thereof without departing from the scope of the present invention.

It can be known from the above embodiments that the receiver calculates the metric value by using the average value of the correlation value of the CP type corresponding to the maximum correlation value, and makes a judgment, so that the cell search result is accurate, and the problems in the prior art are solved. In addition, when calculating the average value of the correlation values, one type of average value or two types of average values may be calculated according to actual conditions.

The above devices and methods of the present invention can be implemented by hardware, or by combining hardware and software. The present invention relates to such a computer-readable program that, when the program is executed by a logic component, enables the logic component to realize the above-mentioned device or constituent component, or enables the logic component to realize the above-mentioned various methods or steps. The present invention also relates to a storage medium for storing the above program, such as hard disk, magnetic disk, optical disk, DVD, flash memory and the like.

The present invention has been described above in conjunction with specific embodiments, but those skilled in the art should be clear that these descriptions are all exemplary and not limiting the protection scope of the present invention. Those skilled in the art can make various variations and modifications to the present invention according to the spirit and principle of the present invention, and these variations and modifications are also within the scope of the present invention.

Claims (7)

1. An apparatus for cell search, the apparatus comprising:

a first processor, configured to perform correlation processing on a received signal and a secondary synchronization local sequence to obtain a correlation value of the received signal and the secondary synchronization local sequence;

a first detector for detecting at least one maximum correlation value from among the correlation values;

a first calculator, configured to calculate a metric value corresponding to each maximum correlation value, where the metric value is a ratio of the maximum correlation value to an average correlation value, where the average correlation value is an average value of correlation values in a cyclic prefix type determined according to the maximum correlation value;

and the first decider is used for comparing the metric value calculated by the first calculator with a preset value so as to determine a candidate standby cell serving as a cell search.

2. The apparatus of claim 1, wherein the apparatus further comprises:

a second calculator for calculating an average of the correlation values in the case of a normal cyclic prefix and/or an average of the correlation values in the case of an extended cyclic prefix.

3. The apparatus according to claim 2, wherein the second calculator is specifically configured to calculate an average value of the correlation values in the case of a normal cyclic prefix or an average value of the correlation values in the case of an extended cyclic prefix, when the number of the maximum correlation values is 1 or the number of the maximum correlation values is more than one and the corresponding cyclic prefix types are the same;

the second calculator is specifically configured to calculate an average value of the correlation values in the case of a normal cyclic prefix and an average value of the correlation values in the case of an extended cyclic prefix, when the number of the maximum correlation values is one or more and the corresponding cyclic prefix types are different.

4. A method of cell search, the method comprising:

performing correlation processing on a received signal and an auxiliary synchronous local sequence to acquire a correlation value of the received signal and the auxiliary synchronous local sequence;

detecting at least one maximum correlation value from among the correlation values;

calculating a metric value corresponding to each maximum correlation value, wherein the metric value is a ratio of the maximum correlation value to an average correlation value, and the average correlation value adopts an average value of the correlation values when the cyclic prefix type is determined according to the maximum correlation value;

and comparing the calculated metric value with a preset value to determine a candidate standby cell serving as a cell search.

5. The method of claim 4, wherein the method further comprises:

an average of the correlation values when a normal cyclic prefix is calculated, and/or an average of the correlation values when an extended cyclic prefix is calculated.

6. The method according to claim 5, wherein when the number of the maximum correlation values is 1, or the number of the maximum correlation values is more than one and the corresponding cyclic prefix types are the same, calculating an average value of the correlation values in the case of a normal cyclic prefix, or calculating an average value of the correlation values in the case of an extended cyclic prefix;

and when the number of the maximum correlation values is more than one and the corresponding cyclic prefix types are different, calculating the average value of the correlation values in the case of a normal cyclic prefix and the average value of the correlation values in the case of an extended cyclic prefix.

7. A receiver comprising the cell search apparatus of claim 1 or 2 or 3.